Photo mask and method of manufacturing thin film transistor using the same

ABSTRACT

According to an exemplary embodiment of the present invention, a photomask includes a transparent substrate and a polarizing pattern. A polarizing pattern is disposed on a transparent substrate. The polarizing pattern polarize light.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to Korean PatentApplication No. 10-2015-0001.361, tiled on Jan. 6, 2015 in the KoreanIntellectual Property Office (KIPO), the disclosure of which isincorporated by reference herein in its entirety.

TECHNICAL FIELD

The present invention relates to a photo mask and a method ofmanufacturing a thin film transistor using the photo mask.

DISCUSSION OF THE RELATED ART

A liquid crystal display (“LCD”) apparatus applies an electric field toliquid crystal molecules to adjust arrangements of the molecules so thatoptical characteristics of a liquid crystal cell is changed fordisplaying an image. Such optical characteristics include birefringence,optical activity, dichroism and/or light scattering.

The LCD apparatus includes a LCD panel to display the image. The LCDpanel is manufactured by using photolithography and etching processes.In the photolithography process, various photomasks are used accordingto patterns to form. As the number of photomasks increases, themanufacturing costs of the LCD apparatus increase.

SUMMARY

According to an exemplary embodiment of the present invention, aphotomask includes a transparent substrate and a polarizing pattern. Apolarizing pattern is disposed on a transparent substrate. Thepolarizing pattern polarize light

According to an exemplary embodiment of the present invention, a methodof manufacturing a thin film transistor is provided as follows. A metallayer is formed on a base substrate. A photoresist layer is formed onthe metal layer. Light polarized at a first polarizing degree is emittedby an exposure. A photomask is provided between the exposure and thephotoresist layer to generate light polarized at a second polarizingdegree. The photomask includes a transparent substrate and a polarizingpattern. The light polarized at the first polarizing degree is polarizedby the polarizing pattern to a light polarized at a second polarizingdegree. The photoresist layer is radiated with the light polarized atthe second polarizing degree. An exposure amount of the light polarizedat the second polarizing is decreased from an exposure amount of thelight polarized at the first polarizing in accordance with a differencebetween the first and second polarizing degrees. A photoresist patternis formed by developing the photoresist layer radiated by the lightpolarized at the second polarizing degree. The metal layer is etched byusing the photoresist layer as an etch mask.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the present invention will become moreapparent by describing in detail exemplary embodiments thereof withreference to the accompanying drawings of which:

FIG. 1 is a cross-sectional view of a photo mask according to anexemplary embodiment of the present invention;

FIGS. 2 to 13 are cross-sectional views for illustrating a method ofmanufacturing a photo mask according to an exemplary embodiment of thepresent invention;

FIG. 14 is a cross-sectional view of a display panel according to anexemplary embodiment of the present invention;

FIG. 15 is a plan view of a first pixel in FIG. 14; and

FIGS. 16 to 22 are cross-sectional views for illustrating a method ofmanufacturing a thin film transistor according to an exemplaryembodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention will be described belowin detail with reference to the accompanying drawings. However, thepresent invention may be embodied in different forms and should not beconstrued as limited to the embodiments set forth herein. In thedrawings, the thickness of layers and regions may be exaggerated forclarity. It will also be understood that when an element is referred toas being “on” another element or substrate, it may be directly on theother element or substrate, or intervening layers may also be present.It will also be understood that when an element is referred to as being“coupled to” or “connected to” another element, it may be directlycoupled to or connected to the other element, or intervening elementsmay also be present. Like reference numerals may refer to the likeelements throughout the specification and drawings.

FIG. 1 is a cross-sectional view of a photo mask according to anexemplary embodiment of the present invention.

Referring to FIG. 1, a photo mask 1 includes a transparent substrate100, a blocking pattern 120, a polarizing pattern 140 and a transmittingpattern 160.

The transparent substrate 100 may support the blocking pattern 120, thepolarizing pattern 140 and the transmitting pattern 160, and thetransparent substrate 100 may transmit light emitted by an exposure (notillustrated) to perform a exposure process. For example, the transparentsubstrate 100 may be a glass substrate or a transparent plasticsubstrate.

The exposure may emit the light polarized at a first polarizing angle.For example, the light may be polarized at the first polarizing angle bya polarizing filter of the exposure.

The blocking pattern 120 is disposed on the transparent substrate 100 toblock the light. For example, the blocking pattern 120 may be formed ofchromium (Cr). In a manufacturing process of a display device, theblocking pattern 120 is aligned with a base substrate such that a regionof the base substrate covered by the blocking pattern 120 remainsunetched in an etching process. In this case, a positive-typephotoresist material may be provided on the base substrate. The displaydevice may be formed on the base substrate.

Alternatively, the blocking pattern 120 may be provided on a region ofthe transparent substrate 100 corresponding to a region of the basesubstrate which is needed to be removed in an etching process. In thiscase, a negative-type photoresist material may be provided on the basesubstrate.

The polarizing pattern 140 is disposed on the transparent substrate 100adjacent to the blocking pattern 120. In addition, the light polarizedat the first polarizing angle may be incident on the polarizing pattern140, and the polarizing pattern 140 may polarize the light at a secondpolarizing angle.

The polarizing pattern 140 may control an exposure amount by using adifference between the first and second polarizing angles. For example,if the first polarizing angle and the second polarizing angle aresubstantially the same as each other, the polarizing pattern 140 maytransmit the entire light incident on the polarizing pattern 140. Inaddition, if the first polarizing angle is substantially perpendicularto the second polarizing angle, the polarizing pattern 140 may block theentire light incident on the polarizing pattern 140.

For example, the exposure amount may be inversely proportional to thedifference between the first and second polarizing angles, and theexposure amount may be adjusted by the difference between the first andsecond polarizing angles.

In an exemplary embodiment of the present invention, the polarizingpattern 140 may include a wire grid pattern.

The wire grid pattern may be a stripe-like metal wire grid patternhaving a line width and spacing that are smaller than the size of therespective wavelengths of red (R), green (G) and blue (B) light, e.g.,within a visible light region detectable by human. The incident light inparallel to the stripe pattern may pass through the wire grid pattern,and the wire grid pattern may perform a polarizing process.

For example, the wire grid pattern may have a stripe pattern having aline width and spacing in a range of about 50 nm to about 200 nm, e.g.,smaller than the minimum optical wavelength of light that is visible.

In an exemplary embodiment of the present invention, the wire gridpattern may include a high reflective material. For example, the wiregrid pattern may be formed of aluminum (Al).

Alternatively, the polarizing pattern 140 may include a polarizing filmformed of polymer resin. For example, the polarizing film may be formedof polyvinyl alcohol. The polarizing film may include light absorbingmaterial which absorbs light vibrating in a specific direction.

The transmitting pattern 160 may be disposed on the transparentsubstrate 100 to transmit the light. The transmitting pattern 160 may beprovided on a region of the transparent substrate 100 corresponding to aregion of a base substrate (not illustrated) which is needed to beremoved in an etching process. In this case, a positive-type photoresistmaterial may be provided on the base substrate.

Alternatively, the transmitting pattern 160 may be provided on a regionof the transparent substrate 100 corresponding to a region of the basesubstrate which is needed to be remained in an etching process. In thiscase, a negative-type photoresist material may be provided on the basesubstrate.

If a design value of a wire pattern formed by the photomasks is changedor if the design value is different from an actual value formed by theprocesses, an exposure amount of each photomask changes.

However, it is difficult to change the exposure amount of apre-manufactured photomask, and a new photomask is needed. Accordingly,until the new photomask having a changed exposure amount is provided, amanufacturing process is stopped to affect productivity.

By a photo mask according to an exemplary embodiment of the presentinvention, the light emitted by the exposure and polarized at the firstpolarizing angle may be polarized at the second polarizing angle.

The difference between the first polarizing angle of the light by thepolarizing filter of the exposure and the second polarizing angle of thelight by the polarizing pattern of the photo mask may be adjusted tocontrol the exposure amount using the photo mask. Accordingly, withoutreplacement of the photo mask and stop of the manufacturing process, athin film transistor may be manufactured continuously to increaseproductivity. In addition, the existing photo mask may be utilized andit may reduce production cost.

Hereinafter, a method of manufacturing a photo mask will be described indetail.

FIGS. 2 to 13 are cross-sectional views for illustrating a method ofmanufacturing a photo mask according to an exemplary embodiment of thepresent invention.

Referring to FIG. 2, a first metal layer 122 and a first photoresistlayer 124 are sequentially stacked on a transparent substrate 100.

The transparent substrate 100 may be provided to support the first metallayer 122 and the first photoresist layer 124. In addition, thetransparent substrate 100 may be provided to support material formed insubsequent processes.

By using Plasma Enhanced Chemical Vapor Deposition (PECVD), sputtering,or Atomic Layer Deposition (ALD) the first metal layer 122 may bestacked on the transparent substrate 100. In addition, the first metallayer 122 may be formed of chromium (Cr).

By using spin coating, spray or roller process, the first photoresistlayer 124 may be stacked on the first metal layer 122. For example, thefirst photoresist layer 124 may be formed of a positive-type photoresistmaterial. Alternatively, the first photoresist layer 124 may be formedof a negative-type photoresist material.

Referring to FIGS. 1 and 3, the first photoresist layer 124 is radiatedby a laser beam emitted by a laser machine 126.

For example, the first photoresist layer 124 includes a first region 128corresponding to a blocking pattern 120, a second region 130corresponding to a polarizing pattern 140 and a third region 131corresponding to a transmitting pattern 160.

The first region 128 of the first photoresist layer 124 is radiated bythe laser beam emitted by the laser machine 126. The first region 128 ofthe first photoresist layer 124 may be hardened by the laser beam.

The second and third regions 130 and 131 of the first photoresist layer124 are not radiated by the laser beam, and the second and third regions130 and 131 are removed in a subsequent photoresist removing process.

Referring to FIG. 4, the second and third regions 130 and 131 areremoved by a developer.

The first region 128 of the first photoresist layer 124 which ishardened by the laser beam is not removed by the developer, remaining onthe first metal layer 122.

Accordingly, by removing the second and third regions 130 and 131 of thefirst photoresist layer 124, the first photoresist layer 124 istransformed into the first photoresist pattern 132.

Referring to FIG. 5, the first metal layer 122 is etched by using thefirst photoresist pattern 132 as an etching mask.

For example, the first metal layer 122 is etched in a dry etchingprocess using plasma such as PECVD, or a wet etching process.

Accordingly, by removing a portion of the first metal layer 122, thefirst metal layer 122 is transformed into the blocking pattern 120 andthe transmitting pattern 160. The blocking pattern 120 blocks incidentlight, and the transmitting pattern 160 transmits the incident light.

Referring to FIG. 6, the blocking pattern 120 is exposed by removing thefirst photoresist pattern 132.

For example, a cleaning process such as an asking process may beperformed to remove the first photoresist pattern 132.

Referring to FIG. 7, a second metal layer 142 is stacked on the blockingpattern 120 and the transparent substrate 100.

A layer deposition process such as Plasma Enhanced Chemical VaporDeposition (PEVCD), sputtering, Atomic Layer Deposition (ALD) may beperformed to stack the second metal layer 142 on the blocking pattern142 and the transparent substrate 100.

The second metal layer 142 may be formed of a high reflective metal. Forexample, the second metal layer 142 may include aluminum (Al).Alternatively, the second metal layer 142 may be formed of a blackmatrix.

Referring to FIG. 8, the second metal layer 142 is planarized until atop surface of the blocking pattern 120 is exposed to form a metal layerpattern 144 filling the transmitting portion 160.

For example, the planarization process may be performed by a chemicalmechanical polishing (CMP) process and/or an etch back process.

Referring to FIG. 9, a second photoresist layer 146 is stacked on theblocking pattern 120 and the metal layer pattern 144.

By using spin coating, spray or roller process, the second photoresistlayer 146 may be stacked on the blocking pattern 120 and the metal layerpattern 144. For example, the second photoresist layer 146 may be formedof a positive-type photoresist material. Alternatively, the secondphotoresist layer 146 may be formed of a negative-type photoresistmaterial.

Referring to FIG. 10, a stamp 148 having a stripe pattern thereon isaligned over the transparent substrate 100, and the second photoresistlayer 146 is compressed with the stamp 148.

For example, an aligning unit may align the stamp 148 over thetransparent substrate 100, and a compressing unit may compress thesecond photoresist layer 146 with the stamp 148.

Then, while the second photoresist layer 146 is compressed with thestamp 148, the second photoresist layer 146 may be hardened by heat.

Referring to FIGS. 11 and 12, the stamp 148 is removed to form a secondphotoresist pattern 150 on the blocking pattern 120 and the metal layerpattern 144.

The stripe pattern of the stamp 148 is transferred to the secondphotoresist layer 146, and the second photoresist layer 146 istransformed into the second photoresist pattern 150 by the stamp 148.

Referring to FIG. 13, the metal layer pattern 144 is etched by using thesecond photoresist pattern 150 as an etching mask, and the secondphotoresist pattern 150 is removed.

For example, the metal layer pattern 144 is etched by performing a dryetching process using plasma such as PECVD, or a wet etching process.Accordingly, a portion of the metal layer pattern 144 is removed totransform the metal layer pattern 144 into the polarizing pattern 140.

In addition, the second photoresist pattern 150 may be removed to exposethe blocking pattern 120 and the polarizing pattern 140. For example, acleaning process such as an ashing process may be performed to removethe second photoresist pattern 150.

When the light polarized at the first polarizing angle by an exposure(not illustrated) is incident on the polarizing pattern 140, thepolarizing pattern 140 may polarize the light at a second polarizingangle.

The polarizing pattern 140 may control an exposure amount by using adifference between the first and second polarizing angles. For example,if the first polarizing angle and the second polarizing angle are thesame as each other, the polarizing pattern 140 may transmit the entirelight incident on the polarizing pattern 140. In addition, if the firstpolarizing angle is substantially perpendicular to the second polarizingangle, the polarizing pattern 140 may block the entire light incident onthe polarizing pattern 140.

For example, the exposure amount may be inversely proportional to thedifference between the first and second polarizing angles, and theexposure amount may be adjusted by the difference between the first andsecond polarizing angles.

In an exemplary embodiment of the present invention, the polarizingpattern 140 may include a wire grid pattern.

The wire grid pattern may be formed of a stripe-like metal wire gridpattern having a line width and spacing that are smaller than the sizeof the respective wavelengths of red (R), green (G) and blue (B) light,i.e., within a visible light region detectable by human. The incidentlight in parallel to the stripe pattern may pass through the wire gridpattern, and the wire grid pattern may polarize the incident light.

In addition, the wire grid pattern may have a stripe pattern having aline width and spacing in a range of about 50 nm to 200 nm, i.e.,smaller than the minimum optical wavelength of light that is visible.

By the method of manufacturing the photo mask according to an exemplaryembodiment of the present invention, the light emitted by the exposureand polarized at the first polarizing angle may be polarized at thesecond polarizing angle by the wire gird pattern.

The difference between the first polarizing angle of the light by thepolarizing filter of the exposure and the second polarizing angle of thelight by the polarizing pattern of the photo mask may be adjusted sothat the exposure amount by the photo mask is controlled. Accordingly,without replacement of the photo mask and stop of the manufacturingprocess, a thin film transistor may be manufactured continuously toincrease productivity. In addition, the existing photo mask may beutilized and it may reduce production cost.

Hereinafter, a display panel will be mainly explained.

FIG. 14 is a cross-sectional view illustrating a display panel accordingto an exemplary embodiment of the present invention. FIG. 15 is a planview illustrating a first pixel in FIG. 14.

Referring to FIGS. 14 and 15, a display panel includes a plurality ofgate lines GL, a plurality of data lines DL and a plurality of pixels.

The plurality of gate lines may extend in a first direction D1. Theplurality of data lines may extend in a second direction D2 crossing(e.g., substantially perpendicular to) the first direction D1.Alternatively, although not illustrated in FIG. 1, the plurality of gatelines may extend in the second direction D2, and the plurality of datalines may extend in the first direction D1.

Pixels are arranged in a matrix form. Each pixel is disposed in arespective pixel area that are defined by a gate line GL and a data lineDL.

Each pixel may be connected to a respective one of the gate lines (e.g.,an adjacent one gate line) and a respective one of the data lines (e.g.,an adjacent one data line).

Each pixel has, but are is limited to, a rectangular shape.Alternatively, each pixel may have a V shape, a Z shape, etc.

The display panel includes a substrate including pixel areas configuredto display image and a thin film transistor TFT. The pixel areas may bearranged in a matrix form having a plurality of columns and a pluralityof rows.

Each pixel area may include a switching element. For example, the thinfilm transistor TFT may be the switching element. The switching elementmay be connected to the respective one of the gate lines (e.g., theadjacent one gate line) and the respective one of the data lines (e.g.,the adjacent one data line). The switching element may be disposed on anarea where the gate line GL crosses the data line DL.

A gate pattern including a gate electrode GE and the gate line GL isdisposed on the substrate. The gate line GL is electrically connected tothe gate electrode GE.

A semiconductor pattern SM is disposed on the substrate. Thesemiconductor pattern SM overlaps the gate electrode GE.

A data pattern including the data line DL, a source electrode SE and adrain electrode DE may be disposed on the semiconductor pattern SM. Thesource electrode SE overlaps the semiconductor pattern SM and iselectrically connected to the data line DL.

The drain electrode DE is spaced apart from the source electrode SE onsemiconductor pattern SM. The semiconductor pattern SM may have aconductive channel between the source electrode SE and the drainelectrode DE.

The thin film transistor TFT includes the gate electrode GE, the sourceelectrode SE, the drain electrode DE and the semiconductor pattern SM.

FIGS. 16 to 23 are cross-sectional views for illustrating a method ofmanufacturing a thin film transistor.

Referring to FIG. 16, a gate electrode GE is formed on a base substrate200. A gate insulation layer 210, an active layer 234, a data metallayer 272 and a third photoresist layer 290 are sequentially formed onthe gate electrode GE and a top surface of the base substrate 200 notcovered by the gate electrode GE.

The base substrate 200 may support material on the base substrate 200,transmitting incident light. For example, the base substrate 200 may beformed of a glass substrate or a transparent plastic substrate.

The gate electrode GE may include at least one of aluminum (Al),titanium (Ti), copper (Cu), molybdenum (Mo), tantalum (Ta), tungsten(W), neodymium (Nd), Chromium (Cr), Silver (Ag), copper oxide (CuOx) andetc. The gate electrode GE may include at least one of gallium dopedzinc oxide (GZO), indium doped zinc oxide (IZO), copper-manganese alloy(CuMn) and etc.

The gate insulation layer 210 may be formed of a transparent, insulatingmaterial such as silicon oxide (SiOx), silicon nitride (SiNx) and etc.

The active layer 234 may be formed of at least one of indium (In), zinc(Zn), gallium (Ga), tin (Sn), hafnium (Hf) and etc. For example, theactive layer 234 may be formed of an oxide semiconductor layer includingindium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), hafniumindium zinc oxide (HIZO) and etc.

The data metal layer 272 may be formed of at least one of aluminum (Al),titanium (Ti), copper (Cu), molybdenum (Mo), tantalum (Ta), tungsten(W), neodymium (Nd), Chromium (Cr), Silver (Ag) and etc.

The third photoresist layer 290 may be stacked on the data metal layer272. For example, the third photoresist layer 290 may be formed of apositive-type photoresist material. Alternatively, the third photoresistlayer 290 may be formed of a negative-type photoresist material.

Referring to FIG. 17, a photo mask 1 is disposed between an exposure(not illustrated) and the third photoresist layer 290, and the thirdphotoresist layer 290 is exposed by light L1 emitted from the exposurethrough the photo mask 1.

Light L1 emitted by the exposure may be polarized at a first polarizingangle by a polarizing filter of the exposure. If an angle of thepolarizing filter is changed, the first polarizing angle may beadjusted.

The light L1 polarized at the first polarizing angle may be incident ona blocking pattern 120, a polarizing pattern 140 and a transmittingpattern 160 of the photo mask 1. For example, the polarizing pattern 140may include a wire grid pattern.

A portion of the light L1 incident on the blocking pattern 120 may beblocked, a portion of the light L1 incident on the transmitting pattern160 may be transmitted, and a portion of the light L1 incident on thepolarizing pattern 140 may be polarized at a second polarizing angle andmay be transformed into light L2 polarized at the second polarizingangle. The light L2 polarized at the second polarizing angle may beincident on the third photoresist layer 290.

An exposure amount of the third photoresist layer 290 may be inverselyproportional to the difference between the first and second polarizingangles, and the exposure amount may be adjusted by the differencebetween the first and second polarizing angles.

A portion of the third photoresist layer 290 disposed under thetransmitting pattern 160 may be more hardened by the light L2 than aportion of the third photoresist layer 290 disposed under the polarizingpattern 140. For example, the portion of the third photoresist layer 290corresponding to the transmitting pattern 160 may be substantiallyentirely hardened, and the portion of the third photoresist layer 290corresponding to the polarizing pattern 140 may be partially hardened bythe light L2.

Referring to FIG. 18, the third photoresist layer 290 corresponding tothe blocking pattern 120 is partially removed such that a first portionof the third photoresist layer 290 remains, and a portion of the thirdphotoresist layer 290 corresponding to the transmitting pattern 160 isentirely removed. The third photoresist layer 290 corresponding to thepolarizing pattern 140 is partially removed such that a second portionof the third photoresist layer 290 remains. The thickness of the firstportion of the third photoresist layer 290 is greater than the secondportion of the third photoresist layer 290. The third photoresist layer290 is transformed into a first photo mask PR1.

For example, a first photoresist pattern PR1 is formed on the data metallayer 272. The first photoresist pattern PR1 overlaps the gate electrodeGE. A thickness of a portion of the first photoresist pattern PR1overlapping the gate electrode GE is smaller than a thickness of otherportion of the first photoresist pattern PR1.

A cleaning process such as an ashing process may be performed to removethe hardened portion of the third photoresist pattern 290, and the thirdphotoresist pattern 290 may be transformed into the first photoresistpattern PR1.

Referring to FIG. 19, the data metal layer 272 and the active layer 234are etched using the first photoresist pattern PR1 as an etch mask, sothat the data metal pattern 272 may be transformed into a data metalpattern 270 and the active layer 234 may be transformed into a activepattern 232.

For example, a portion of the data metal layer 272 and a portion of theactive layer 234 may be etched by performing a dry etching process usingplasma such as PECVD, or a wet etching process.

One etching process for the data metal layer 272 and other etchingprocess for the active layer 234 may be performed simultaneously orsequentially.

Referring to FIG. 20, a second photoresist pattern PR2 is formed bypartially removing the first photoresist pattern PR1. The secondphotoresist pattern PR2 is formed by partially removing the firstphotoresist pattern PR1 in a thickness direction. For example, thesecond photoresist pattern PR2 is formed by removing the first portionof the first photoresist pattern PR1.

A top surface of the data metal pattern 270 is partially exposed by thesecond photoresist pattern PR2. For example, a central portion of thetop surface of the data metal pattern 270 is exposed.

Referring to FIG. 21, the data metal pattern 270 is etched using thesecond photoresist pattern PR2 as a etch mask. An exposed portion of thedata metal pattern 270 is etched, so that source and drain electrode SEand DE may he formed.

A portion of the active pattern 232 may be removed by using the secondphotoresist pattern PR2 as a etch mask. One etching process for the datametal pattern 270 and other etching process for the active pattern 232may be performed simultaneously or sequentially. Alternatively, theetching process for the active pattern 232 may be omitted.

Referring to FIG. 22, the second photo mask is removed to expose thesource electrode SE and the drain electrode DE such that a thin filmtransistor is manufactured. For example, a cleaning process such as anashing process may be performed to remove the second photo mask PR2.

By the method of manufacturing the thin film transistor according to anexemplary embodiment of the present invention, the light emitted by theexposure and polarized at the first polarizing angle may be polarized atthe second polarizing angle by the wire gird pattern.

The difference between the first polarizing angle of the light by thepolarizing filter of the exposure and the second polarizing angle of thelight by the polarizing pattern of the photo mask may be adjusted tocontrol the exposure amount by the photo mask. Accordingly, withoutbreak of a manufacturing process to replace a photo mask, a thin filmtransistor may be manufactured continuously to increase productivity. Inaddition, the existing photo mask may be utilized and it may reduceproduction cost.

While the present invention has been shown and described with referenceto exemplary embodiments thereof, it will be apparent to those ofordinary skill in the art that various changes in form and detail may bemade therein without departing from the spirit and scope of theinventive concept as defined by the following claims.

What is claimed is:
 1. A photomask comprising: a transparent substrate;and a polarizing pattern disposed on the transparent substrate andconfigured to polarize light.
 2. The photomask of claim 1, wherein thepolarizing pattern includes a wire grid pattern.
 3. The photomask ofclaim 2, wherein the wire grid pattern includes a high reflective metal.4. The photomask of claim 2, wherein the wire grid pattern includesaluminum (Al).
 5. The photomask of claim 2, wherein the wire gridpattern has a stripe pattern.
 6. The photomask of claim 5, wherein eachpattern of the wire grid pattern having the stripe pattern has a linewidth of about 50 nm to about 200 nm.
 7. The photomask of claim 1,wherein the polarizing pattern includes polymer resins.
 8. The photomaskof claim 1, further comprising: a plurality of blocking patternsdisposed on the transparent substrate, the polarizing pattern providedbetween the blocking patterns.
 9. The photomask of claim 8, wherein theblocking patterns are formed of chromium (Cr).
 10. The photomasks ofclaim 1, further comprising: a transmitting pattern disposed on thetransparent substrate, the transmitting pattern transmitting the light.11. A method of manufacturing a thin film transistor, the methodcomprising: forming a metal layer on a base substrate; thrilling aphotoresist layer on the metal layer; emitting light polarized at afirst polarizing degree by an exposure; providing a photomask betweenthe exposure and the photoresist layer, wherein the photomask includes atransparent substrate and a polarizing pattern and wherein the lightpolarized at the first polarizing degree is polarized by the polarizingpattern to a light polarized at a second polarizing degree, radiatingthe photoresist layer with the light polarized at the second polarizingdegree, wherein an exposure amount of the light polarized at the secondpolarizing degree is decreased from an exposure amount of the lightpolarized at the first polarizing degree in accordance with a differencebetween the first and second polarizing degrees; forming a photoresistpattern by developing the photoresist layer radiated by the lightpolarized at the second polarizing degree; and etching the metal layerby using the photoresist layer as an etch mask.
 12. The method of claim11, wherein the emitting of the light polarized at the first polarizingdegree includes: emitting the light polarized at the first polarizingdegree by using a polarizing filter of the exposure.
 13. The method ofclaim 11, wherein the polarizing pattern includes a wire grid pattern.14. The method of claim 13, wherein the wire grid pattern includes ahigh reflective metal.
 15. The method of claim 13, wherein the wire gridpattern includes aluminum (Al).
 16. The method of claim 13, wherein thewire grid pattern has a stripe pattern.
 17. The method of claim 16,wherein the stripe pattern has a line width of about 50 nm to about 200nm.
 18. The method of claim 11, wherein the polarizing pattern includespolymer resins.
 19. The method of claim 11, wherein the photomaskfurther comprises: a plurality of blocking patterns disposed on thetransparent substrate, and wherein the polarizing pattern is providedbetween the blocking patterns.
 20. The method of claim 19, wherein theHocking patterns include chromium (Cr).